This actually just happened to me back in January.
Basically, a random man showed up at my boyfriend's previous job and said he had a "meeting" with my boyfriend. The guy acted jumpy and weird. My boyfriend stated that he did not know who the guy was and asked if he would please refresh his memory if he had actually forgotten something. Then he ran out of the joint. My boyfriend, being a firefighter and part-time deputy followed the guy and ran his plates. He found this guy's facebook and contacted him asking why he had been there and that if he did not get a response by a set time, he would be filing a report for attempted robbery.
The guy finally responds and says that he had been talking to my boyfriend on Grindr for the last two weeks, but when my boyfriend had no idea what was going on, he got embarrassed and bolted.
My boyfriend's first reaction was to ask if I had set it all up to see if he would cheat on me. About a month before we'd had a discussion about his coming out as being bisexual and I guess he thought I was terrified he'd leave me for a man.
I was hurt that he asked, but I understood he had a valid fear. I waited a moment before I replied and simply stated that no, I had not done it.
But he didn't believe me. And then later I found on Whisper that he had posted that he thought it was me all along.
It's basically put a giant hole in our relationship and I don't know if it can be repaired at this point.
Either someone else made a fake Grindr account in his name with the intention of tearing us apart, or my boyfriend made the account himself, chickened out at the last minute and was trying to put the blame on anyone but himself.
Either way, while I was enraged, I tried to acted poised and polite that he accused me of doing it. Didn't work out too well because it meant that he didn't/doesn't have trust for me.
I actually went through quite a bit of trouble and emailing to try to prove it wasn't me, but in the end Grindr would only work with the local authorities to try to figure it out and since I wasn't directly involved in the "fake profile" I didn't have the right to take it to the police.
He apologized for accusing me of it, but since then I've been at arm's length from him.