Lately i have not been able to keep my erection up for a long time now what can !

Lately i have not been able to keep my erection up for a long time now what can i do ?

ok this has only happend to me recently it has never happened it happened at my girls house i was in the middle of it when it just went down it happened two nights in a row and of course i got uoset and its a little embarrasing and we have always done at her house when every body is asleep, or is it because ijm not relaxed , any answer would be great to help me!

2 weeks ago
like i said its just happened recently other times we had intercourse it never happened?

What can you do to maintain an erection?
Toothpicks and duck tape!
I have always wanted to say that. Now it is out of my system.

Anyway. Seriously, on to your issue.
It is not uncommon for adult men to have episodic instances of inability to get an erection or inability to maintain an erection. I agree when it happens, it is embarrassing. On those instances you can really tell the quality of the woman you are with. The really good women, don't further add to the embarrassment by jokes (oh, my gosh, that is what I just did, sorry!!!!!!) or other ways to make you feel inadequate.
As for the cause, assuming you are healthy, it can come from fatigue, stress, anxiety (fear of being caught - you said you usually are sexual when everyone is asleep.) tension, or just plain distraction.
Health related issues can include: medication side effect, diabetes, etc. If you think it is medical see your Doc.

NOW THIS IS REAL IMPORTANT: If it happened once or twice, your are going to be hyper-vigilant and hypersensitive about it. If you start to worry -- Oh God, is it going to happen again tonight -- the stress and worry will probably make it happen again. Just relax, take it easy and let nature take it's course.

Hope this helped and sorry for the joke part.