I make use of trimix for over 7 years with good results (except when I apply it wrong

I don't do the application before starting the sex with my wife. First we do some foreplay (kisses, fingers, oral sex) then I do the application of trimix going back to foreplay and when my Dick this hard started the penetration. I ejaculate after 25 to 35 minutes depending on the rhythm of penetration.
After ejaculation I have a loss of erection. I learned over time that I stand for a few minutes my erection back quicker and firmer. But in the second round I don't ejaculate I penetrating my wife for a long time. Another thing that happens when I do anal sex my Dick gets harder and my wife speaks which is thicker.
I'm not too bothered by not ejaculating in the second round because my wife is happy but sometimes me and her we get frustrated because I didn't ejaculate. I would like to know if anyone here have this problem or have been through this situation.