At the end of the day wear what you like and feel comfortable in. Especially around the house obviously nobody will see. But I tell him people are more likely to notice the girl dressed like a 16 year old in 2007 lol.
We go to concerts a lot where he blends in a little more dressed like that, but I started buying him clothes more appropriate for a girl in her late 20s for when we go out. They still have a lot of fun and cute stuff he likes. Older doesnt have to mean boring.