Why is my penis not really hard

My penis is hard but its not really hard. How do I get it to be really hard

Stop playing with it as much, it's tired.

its when my girlfriend starts giving me a handjob but my penis is still not very hard

Ah then sorry for the jump to conclusion.

It could be over-stimulation possibly same as it would be with masturbation, or it could be that your really NOT that aroused.

Mostly likely your not in the mood/ not aroused.

Viagra.

I am a geezer and I can understand what you mean.

Sometimes I'm just so horny my erection will be so hard it will actually be painful.

However sometimes...when my girlfriend just sort of grabs it and wants a play...it wont get quite as hard...and will often lose the erection if she lets go.

But I'll still her her do it anyway lol.