with the couple i have at the moment, i positioned the male right behind her, within about 10 seconds he jumped on and got right down to business, no hitching a lift. he spent the next 15 minutes or so manoeuvering his abdomen round for the connection. he finally did, they stayed connected for a few hours, then the male disconnected and jumped away frantically. the only activity from the female was looking round at the male before he got on, then looking straight ahead again, as if to say "oh its only you".
however, i tried re-mating them again today (and also last friday) but these two times the male didnt seem as eager to get on at all, and instead begun waving the forearms like they do before a threat display, and flashing the wings out a bit. she was having none of it either, as soon as he made a movement she turned round, flashed the wings once. she faced forwards again and just started slowly walking away. he carried on flashing his wings and waving his forearms, so she turned round and gave him whatfor. its the best ive seen him fly. she was very well fed both times.
ive bred p.wahlbergii once before, years ago, and it went very smoothly. but i did see the wing flashing you described today, though they had already mated and apparently pw females arent too keen on being remated, i think. but as its your first mating of the pair, its quite unusual i think. how long have they been adults?