firstly pia resembles maithili abhay's lost love
so he has the same feelings for pia when he sees her face . maybe his father chand (mr.raichand ) must have killed maithili because maybe she knew they were vampires and his father got scared that she will expose them .so after her death he doesn't want pia to fall in love with him and again the whole history of maithili to be repeated by pia. so if he becomes rude to pia she will hate him and stay away from him and then she would be safe. but whenever he sees pia with kabir he gets jealous because it is like maithili with kabir so thats why he becomes all childish . because maithili is his possession and obsession .
seconly its not mr raichand who made maya pregnant . actually maya was a weird girl trying to commit suicide but abhay saves her and because of this she is behind him to take her responsibility.
and so obviously abhay is the better lover the true lover who cares about pia or u can say maithili