it is difficult to say how long it will take to ejaculate when you are involving sex. but your short ejaculation time mostly due to psychological factors. there are methods you can delay ejaculation .one method is calling as squezzing method. you can squezz your glan penis when you feel to cum.it will stop sperms coming out and delay the time. other thing you can do is stop start technique . when you feel to cum you can stop for moment and restart. this will also increase your time. other thinng when you are involving sex there is more time forplay like kissing and hugging. that will also more relax and reduce your anxiety and increase your perfomace . so you dont have to worry much about that. when you areb barthing retract your foreskin and clean daily. it will prevent slight irritation and injuries.anyway if you have persistnat problem with early ejaculation after marriage you can get the help of a psychiatrist.