Guys, what would you do if your girlfriend was tense while naked?

I find it hot when they're nervous

I would hug her from behind for a while and talk softly and sweetly to her, perhaps sit her on my lap and pet her hair

When presented with sweetness and gentleness, you're more likely to be comfortable and feel a warm feeling of affection and safety

And the feeling of that nervousness and nakedness builds over time to more and more arousal, sweetly rub the clitoris while holding her affectionately, it will take so little to make a nervous woman orgasm if you play it right

That is a normal reaction, especially when young.
The older you get, the more relaxed you are.

Assure her that she doesn’t need to be tense or worry, and take it very slow with her. Give her a chance to ease into the new experience without feeling scared

Have her put something on if she’s more comfortable.

Pull a robe over her and bring her to the bathroom and start and hot shower turn off the lights guide her into the shower and then slowly start soaping and washing in the dark till shes not so embarassed

Don't force her to strip if she's uncomfortable.

The hardest thing is to persuade a girl to let you take her virginity,once youre in a sexual situation you have to really take charge and be firm that this is going to happen.By "firm",of course i do not mean "force",but be gentle and reassuring.
I find some girls are nervous of erect penises,but you have to let her see it and be brave.

Try to relax her. Comfort her. Reassure her.