I would tell them the truth of having a fiancé in the US who I miss smch, I wish to have my studies and also spend some time with her while my study is on going. After which I would return to my home country . This is what I feel I will tell them and if granted F1 visa, then I’d withdraw our K1 application and then go for AOS. Hearing is an immigration fraud makes me weak cos I don’t know what to do anymore