i think love bombing or "fauning" is a defense mechanism for ppl who really want to be liked. agreeable men will do it because they fear being rejected, it probably comes across as manipulative because on some level it is, because the person is laying on the positivity to protect themselves from negativity/rejection. They want sex, but you saying no would hurt so they instinctual dump affection to get the desired result

fauning as a psychological phenomena is different from sociopathic flattery because it comes from a place of vulnerability rather than cold, calculation. fauning behaviors come from emotionally abusive childhoods, in the case of guys it probably comes from women who were way too critical of them as children which turns into this chronic fear of rejection that manifests with manipulative strategies.