New sheets

I asked my boyfriend to get new sheets. I offered to pay for them but he said no. I have been asking for awhile and he finally ordered them today. He just thinks I don't like them. I didn't tell him the real reason.

The real reason is because he hasn't gotten new sheets since his last relationship and I've just always been uncomfortable sleeping and having sex on sheets that he's fucked another girl on.

Is that ridiculous? It feels ridiculous but I don't know, it just has always made me feel gross. (We will have been together for 7 months in two weeks).