There's no way to tell without asking them. In gay communities the boundaries between friends and romantic partners are blurry.
You have sex with friends, and often you don't with partners.
You sometimes live with friends, and sometimes live separately from partners.
Looking in from outside the relationship, it's hard, sometimes well-nigh impossible, to tell them apart.
But inside the relationship, you know. He is a romantic partner, with emphasis on the romance. You are in love with him. It is intense, passionate. You want to spend every moment with him, to walk by his side into the future.
The beginning of a friendship is fun. The beginning of a romance is thrilling.
The end of a friendship is sad. The end of a romance is devastating.
I grew up with dreams of a life-long partner, one boy to wake up next to every morning through the years and decades. But living in gay communities takes a tremendous amount of work and a lot of luck -- apartments are expensive and jobs are scarce. So after six months, or a year, or five years, he moves away, or you move away, and you become ex-boyfriends, relegated to occasional visits at Christmas or spring break.
And suddenly you're 56 years old, and you've had 16 romantic partners:
College1. Fred the Ministerial Student. About six months in the spring of 1980, my sophomore year in college. When he moved to Omaha to take a church, I moved with him.
Why it ended: He got controlling, and I didn't like him cruising other guys, so I left. We stayed friends.
2. Peter the Greek Orthodox Priest. Actually an ex-priest, now an insurance salesman. About two months in the fall of 1981, my senior year.
Why it ended: I couldn't take his drinking or his weird pushy mom, who kept asking strange questions and once burst in on us in the bedroom..
3. Jimmy the Bodybuilder on Crutches. A grad student in social work. About three months in the fall of 1983, when I was at Indiana University.
Why it ended: He dumped me for another guy.
The full list, with nude photos, is on Tales of West Hollywood.