You can kindly point him to do some research! There’s a lot of great YouTube content out there for instance. Helena Nista is a sex therapist and her videos have helped me be a better lover.

That’s just one instance. There’s a lot of good information out there - he just needs to be open to it and be confident. When my girlfriend told me I didn’t take it as a slight on me, I took it motivation to please her better.

Hope this helps! Good luck and I hope it works out