Yes. Not touch any & wet his underwear.

Mentality has strong impact on PE. Ask ur bf try not to get too excited when comes to making love, put it in a calm and relax mood. Stress and pressure knowing that ur bf will PE will make it worse. Try not to think that “I've PE problem" every time you two making love.

I know that there's one exercise to reduce sensitivity of penis head. Try to massage the penis head while using hot shower on it, then switch to cold shower, repeating the same.

PS: circumcision is a good way to reduce penis head sensitivity but requires some time.