Jerking off before sex

I think my SO has started jerking off before we have sex. Normally he lasts around 3mins. It's not hard for me to get him off til round two. Anyways the last two mornings it's taken over 10mins and this morning he couldn't even get hard which never happens. We showered together and then were heading to the bed room but I waited almost 10mins for him to come upstairs and then he couldn't get hard he tried for around 10-15mins he was just hard in the shower and then decided to go down on me and after that he was able to get hard but not get off. I understand him wanting to last longer for me, but it makes me insecure when he can't get hard or get off. And if I confront him he will just deny it. 🙄 he's so easy to get hard too so I just know he's pinching one off. 😑