POints to be noted: 1) She is 19.. a mere adoloscent who cannot even tell you straight that she likes you because she doesnt speak a language you understand and most probably vice versa! (communication gap??) 2) Your impulse to have something with her might affect 2 women in the future (her and your to be wife). 3) Brazillian women get hurt too if abandoned. (Even though she might be wanting a green card from you!) 4) You asking advice and stating that you might get engaged in 3 months with someone else. (Getting your conscience cleared about thinking of getting a teenager laid??) 5) You seem to know what point you are standingoin. Some people have higher ethics and some have lower. You know what you have to do.whatever your conscience tells you. why asking for advice when you know you wont follow it?