Anna Wineheart Books

MMM, Non-con, 2 victims

The ad sounds too good to be true: $100k to participate in a study. All Brey needs is to set up some cameras in his bedroom and wear a low-frequency buttplug every night for two months straight.
Nothing happens at first… until he wakes up one night with a monster in his bed. A huge monster with tentacle-y vines.

31k words (155 pages), HEA

Main warnings: noncon, somnophilia (sleep smut), vines as tentacles, forced breeding
Other warnings: monster peens, sounding, noncon by bad guy, blowjob, DP, public smut/exhibitionism, (briefly: tail smut, knotting, cock slapping)