You've said that you're aware that really any woman - no matter what her age, is going to be an issue for you. I think you've become so determined to experience what you feel is necessary at your age, you're unsure if you even want it. If you're having doubts you either need to explain that you don't feel you're ready at the moment or carefully describe how you feel in the hope that you both reach a resolution.

Now, most 26 year old people will probably understand and if they allow for you to elaborate, explain that you're concerned about what it is you would have in common. DON'T MENTION THE AGE GAP - unless she suggests it and this may give her the chance to take the pressure off and suggest a more engaging activity that won't let you dwell too much on the minute by minute details of the date or whatever it is you want to call it. To be honest if you've got on well up until this point then clearly you do have SOMETHING in common and i don't see why the transfer over to a real life situation would somehow stunt that.

I know most people suggest that going to the cinema is uninventive and doesn't allow for a lot of conversation. In your case that might be a good thing - it will help you determine whether you can just be comfortable in her company and want to get to know her more without a lot of continuous back and forth to cloud your thinking. All being well afterwards, you can grab a bite to eat and have the movie as something to discuss - it's the reason why the cinema has been fool proof for so long and shouldn't be undervalued!

You just need a bit of tact and remember that you too are an adult despite how inexperienced you feel in this aspect. If you don't want to pursue this sort of thing at the moment then as an adult you reserve that right. You also have a right to express how you feel. Try and focus on how empowering it is to have those possibilities at your command rather than feeling like a kid who's got to choose between having a clown or a bouncy castle for his birthday. If you don't go out with this girl, at least it's some experience you've gained and there will plenty of time to do it again. There is NOTHING to lose and EVERYTHING to be gained. You've just got to adjust your mindset a bit better.