Your titas will of course have a lot to say & really insist -- they are helping you, so translation: may k to PAKIALAM. But bottom line, they love you. Bottom line, ayaw nila malagay ka sa ewan na situation. Sa matatanda kasi, money is the easiest problem to solve. Oo mahirap to get more or enough of it -- but, as my Lola says -- of the major problems, it is the most "solvable". Unlike a philandering husband, a child with a birth defect, a degenerative disease, a pregnancy out of wedlock, a bwis*t MIL, etc etc etc -- you get the drift?
As you say: bihira naman your bf is there. So, the path of least resistance is to continue what you do -- hide him when somebody drops by.
Why can't you marry now? The usual answer I get is: we are saving for a grand wedding; but you didn't say that. IF he marries you now, ganon pa rin naman: he keeps his job, he doesn't get a pay cut, LDR pa rin kayo, you both help your mom. There is no financial deterrent nor negative result if you marry now. Makaka save pa rin sya -- kasi he MUST, so he WILL save for his training & exam. Que single or married, que sharing your expenses or not -- he will do what it takes as his career path requires. So, that poofs away your side of the argument. Hindi kita pinapakaba - I just want you to think more, and go through all this with eyes wide open.
He says he wants to marry when he is more financially stable. Fine, respect that. You have no choice really but to wait -- if you want to gamble/hope on marrying this guy.
IMO, but what do I know, really?: Continue hiding him quesa you take the tiring stance of being on the defensive with your talkative aunts. AND be sure your birth control choice is darn effective. I have seen some so-in-love men turn cold pag sila eh na bulaga, as in: I'm pregnant! That kind of announcement screws up their plans, & some resent it forever. Just saying.