Did you know that some sea slugs lose their penis when mating but it grows back again? Apparently this has been observed in the sea slug Chromodoris reticulata.
This interesting article led me to making a comparative table of human and sea-slug sexual activity for your edification. Who knows, you could be in a pub quiz one day and it might come up (a question about sea slug sexual behaviour might come up, what did you think I meant?).
So, luckily human sex is more fun that sea slug sex, even though we can’t change sex at will. We can also last longer than sea slugs if we have the right method.
One most important thing to understand is that men get turned on quickly but women take longer to be ready – you have to create the mood. Today, though, I’m going to assume you’ve done that and things are going well, but you’re at risk of coming before she does.
A really excellent way of stimulating her without coming too soon
With you on top, rub the underside of the shaft of your penis against her clitoral area (see figure). You don’t have to worry about exact positioning because her vulva will more or less guide you into the correct area.
You can then thrust against her without being inside her. The stimulation you are getting is on the relatively less sensitive shaft of the penis, but the stimulation she is getting is fairly maximal.
I would add that if even that starts to get too much for you then continue clitoral stimulation with your fingers.