I had dated a deputy ( county employed ) and he used to stay over, so I know that he had no requirements regarding underwear. He wore colored boxer briefs, boxers and CK briefs from what I remember. He had a streak of jealousy that just didn’t fly with me. He would get jealous of me talking to single gay men. Never mind that conversing with gay men was a major part of my job and it was how he met me. I wished him well and explained numerous times that I never cheat on someone, so I helped him pack up that underwear and some other clothes that he kept at my house and sent him on to the next guy. From what I know, he hasn’t been in a relationship since. ( I am not stalking him; I remain good friends with some of his friends.)