Even during my slutty phase (yay for bad decisions after traumatic things) I didn't ask for proof of STD status. I just kept myself tested on a very regular basis.
After I got out of that I hit a point where I decided I wouldn't have sex with someone unless I could trust them to be honest to me about their status and making sure I had tests done before and after (a couple of tests with 6 weeks between) having sex with a new partner.
Worked so far.
Woodsmith: My husband
Merry: Tig's wife/slave
N8: Merry's boyfriend/owner
Elle: N8 girlfriend
Ruby: Part of the Leather Family
Logan: Leather Sir in the Family
Arc: Logan's boy
Holly: Leather family
K: Holly's sub