Gay Twin Brothers? Nope, just another creepy gay couple

Has anyone out there ever realised that in a lot of gay couples (A LOT) one looks almost exactly like the other physically? And am I the only one slightly creeped out by it? I know for a long time that we gay men have exaggerated narcissistic tendencies, something that begin as a defence mechanism I assume, but that is taking narcissism to a whole different level. I suppose it can be argued that it does happen on straight couples as well (Barbie & Ken exemplify that perfectly) but maybe it's more shocking on gay couples. I mean...one quick glance on Grindr and what is one of the most common requests? "Looking for similar". I don't know why this bothers me but it does, maybe because my ex bf's were all quite different from me physically. But if a guy chooses an almost identical twin to be his boyfriend, does that mean he has an incredibly high self esteem?