Potty Training

Any other potty training moms out there reading this ... I could use some input. Houston is what I call "naked potty trained". If he is naked he comes and gets me every time he has to go and says either "pee" or "poo". He holds it until we get to the potty and then he goes. He has been doing this for at least a month now. I'm glad it's summer because if we are home then he is naked. And I do realize that he is really young to be potty trained this far being that he just turned two last week and he is a boy. I'm not sure why boys supposively potty train later than girls but that's what the statistics say and who am I to argue with numbers?! So here is my problem ... if he has a diaper or underwear on he just goes ahead and pees in them most of the time and doesn't tell me he has to go until he has already gone. He will still tell us he has to "poo" so as far as that goes he is basically potty trained. How do I get him to tell me he has to pee when he has clothes on? My thinking so far is that if I can keep him naked as much as possible then every time he pees on the potty it is being reinforced that it is good to pee on the potty. I explain to him when we try underwear on that he still has to tell me when he has to pee. So far this is not working so well. And hey ... i'm all about a little naked boy running around the house so "naked potty trained" works for me for now but I do want to leave the house once in a while. Any suggestions moms?