Ask yourself what you find attractive, and what turns you on. Get over emotional baggage from previous relationships. If he is truly interested in you and no longer interested in his wife, he'll get a divorced. That just may be his natural tendency. They may still experience sexual attraction.
However you might find that you are no longer sexually attracted to them, but still romantically attracted.
AO Angel Olivo Jun 2, Be whoever you feel like being. Do something to make life wonderful for your partner, each and every day. Don't do anything that will put you in an unsafe situatuion. But, if you've gone through the trouble of approaching a guy and you end up getting his number, follow up with him. Understand that narratives abound about why one develops a particular sexual orientation.
Do nice things for them. How do I know if the girl I like is a lesbian, too? An educator once said "A therapist's job is to help you find out what you think; if they tell you what they think you are, then they aren't a good therapist. Understand a bit about what science says about being gay. Wait until you are making eye contact and cuddling to go in for the kiss.