Honestly this is a mental problem. If you're convinced you're not going to like something - anything you will not. The proverbial self fulfilling prophesy. Being a straight guy - I can only guess that semen - like beer, wine, etc is an acquired taste. I'm sure you can think of many foods you didn't like the first few times you tried them - but eventually you learned to eat your peas!
For the first 15 year of our marriage my wife anticipated my orgasm and either pulled back or let the semen dribble out. About 5 years ago my wife decided to go for it - she tries to deep-throat me and swallows every time. When I asked what changed she just said that she decided to try to make me feel as good as I did for her.
Talk to your husband - get him to warn you (if you can't already tell) before he has an orgasm - back away and finish him with your hands. As you get comfortable with that - you may try to keep him in shallow enough to control the flow allowing it to dribble out. Once you get use to the taste you may decide to go all the way. Basically its a desensitizing process.
BTW - the pineapple works pretty good!
Enjoy your husband and I'm sure he'll reciprocate!