I think any good relationship will make you friends, and it isn’t awkward, it’s great! But having been married a while, it is something you need to work at. With a long term partner they can end up in a bunch of different types of relationships with you - as well as friend, romantic parter and lover, they might be the equivalent of business parter, or boss/employee (for various household and family chores / projects) and learning how to do all those things well, and without ruining the other parts of the relationship can be challenge.

But if the balance is just between ‘friend’ and ‘gf’, I’d say the trick is knowing when to prioritise one over the over. There are times I’m horny and want to take things in that direction, but I realise my partner would rather have a cup of tea and complain about work. Equally, we might be getting intimate, and I’m tempted to make some dumb joke, because it’s funny and that’s what I do with a friend, so I have to weigh up my priorities (mostly sex wins, but sometimes I say the dumb thing and we both have a big laugh and then make dinner.)