if you do it you will get caught! and the girlfriend is at an age where she dont wanna be messed around by a bloke especialy not for a 19 year old girl!
i was never happy unless i was juggeling 2 women, in the end it cost me
no matter what they say all women are the same and can dump on you at any minuite for no reason!
end of the day you dont wanna end up single so if you think the 19yo is up for time then maybe give it a shot
or get the GF to go with the rich bloke and still jump her on the side with the oldmans cash, wile you go out with the 19 yo and work your way through her mates
Sam