That depends entirely on what you are saying and to whom.
If a woman says to me: "Man your tits look awesome tonight!" instead of complimenting the outfit I'm wearing by saying it looks nice on me, I would think there was something a little deeper she was trying to say.
I agree that it depends on what, exactly, you say.
I ALWAYS notice attractive people, whether they are men or women, and I admire from an aesthetic standpoint whichever features make them most attractive to me. I have been known to compliment people on their eyes, their hair, their teeth (I absolutely LOVE a beautiful smile on anyone), their clothing/shoe choices, and (especially) personality traits (empathy, attention to detail, tactful communication, quick wit, excellent insight, humor, etc.), but I always make every effort to be tactful and sincerely respectful. This means I won't shower people with a barrage of compliments but will choose one or two things that I think would mean the most to the person complimented. For example, if it is obvious that someone puts a lot of effort into grooming his/her hair, then presenting a polished and groomed appearance is obviously important to him/her, so if I think his/her hair is gorgeous, I will tell him/her so. If s/he is obviously a careful dresser and I love his/her shoes, I won't hesitate to tell him/her. And if I really think so, I will tell him/her that the entire outfit looks nice.
But I try to be mindful with compliments because I don't want people to feel uncomfortable or feel as though they are being ogled. If a person EVER shows any sign of discomfort from receiving a compliment, I would take that as a cue to back off and be more formal and respectful.
The most respectful and thoughtful compliments are those that show appreciation for a person's core being: his/her tastes, values, insights, and choices/actions. Telling someone that s/he is an excellent parent, son/daughter, or friend is perhaps the most meaningful of all.
Even though I am straight (or perhaps I should say BECAUSE I am straight and in a committed marriage), I am much, much, MUCH more likely to compliment a woman. I usually just keep my opinion about a man to myself rather than risk being perceived as coming on to him.
My compliments are always G/PG-rated though, no matter who I compliment, because anything more than G/PG-rated DOES come across as a sexual advance. And any compliments that could be construed as a sexual advance are reserved for actually USING them as a sexual advance! Since I'm monogamous, my husband is the only one who receives those kinds of compliments from me.
I can't really vote on this. I really am bi (though it's not the term I would use), but I also find a lot of beauty in women I'm not attracted to.
Okay, just like you're not attracted to every man you see, I'm not attracted to every man or woman I see. In fact, I'm rarely attracted to anyone. There are people that I find attractive on a very basic level, but to really capture my attention, there is so much more involved.
But I think I misunderstood. Anyway, people tend to be wary of compliments. They might read something into a compliment because they can't imagine that someone would compliment them without having ulterior motives.
I am able to identify that a woman is "hot" or "ugly" without looking at her sexually. I will often say "she is so hot" about a woman, but I'm not getting wet over it or anything. Every now and then you just see one of those women with perfect breasts and body measurements (or at least the way you want to look yourself. i think nobody is imperfect, i just can't find better wording to explain this). I have a tight friend circle, and you can seriously always find us grabbing each others breasts or butts or cooches and it's all fun and play. We'll even say "your boobs got bigger! they look good!" when changing in the same room or out at the pool. But I guarantee you never see me fantasizing about being in bed with one of my friends.
The only way to know if there is are hidden bi-sexual or homosexual tendencies is based upon what you know and feel.
It's perfectly possible to find another woman aesthetically attractive without being sexually attracted to them, yeah.
As for why these women think you're bisexual and into them, it could depend on what you're saying, yeah. And keep in mind, it's not like you have anything on you like a nametag that says "hello, I'm heterosexual", anymore than bisexuals or lesbians or gay men have any sort of marking. You can't really tell someone else's sexuality, and that's kind of the curse of bisexual women and lesbians; we find ourselves hitting on cute girls only to find out that they're straight. It's not so much that we think you're bi as it is that we don't know and are hopeful when that happens.
Anyone can find members of the same sex attractive without wanting sex. For example, a lot of people assume that I'm bisexual, because even though I only date men, I have a huge collection of vintage pin-ups in general and Marilyn Monroe in particular. But... I'm not bisexual or bi-romantic. I do not find female genitalia appealing, and though I form my closest friendships with other women, I am not interested in moving those relationships beyond friendship.
Women may say nice things about other women, without wondering happening. I've had men say nice things about my appearance without assuming that they were sexually interested in me, so I think it's just fair to not take innocuous comments about looks as compliments, rather than come-ons.
I get where you are coming from. Straight girls tell straight girls they look pretty or have cute clothes or whatever all the time... while shouldn't you be able to do that to someone who might be attracted to you. You just have to be careful about how it comes across. Have they been flirting with you before that? Where are you and who else is around? I think though that you shouldn't feel insecure about your sexuality, and I'm sure they don't doubt you as much as they are just curious. It's a compliment.