I've been going through and having to do some clean up on images given the hetero tag, while some of them are pretty obviously incorrectly tagged (post #691745, yaoi; post #960803, yuri; post #36239, true solo; post #34588, futa_with_male), there are others that seem kind of gray. I'd like some clarification on whether these really should be tagged with the hetero tag (I've already removed the hetero tag from at least some of these, but will re-add the tag to them as needed):
Forced stripping: post #527904
Lifting up a character's clothing: post #224847
Females that have been ejaculated on/in (after_sex) with no other male presence but the cum: post #260989, post #266833, post #207745
Same as previous, just also depicting with them things like used condoms or other gear: post #258158, post #259643
Animated gif of female character with movement indicating being thrust into, partner not shown: post #271269
male and female together nude (no sex): post #1389131 (mixed bath), post #1339818 (classroom), post #317961 (bath)
Hand holding, partner not visible: post #242381
Girl holding the arms of two guys: post #529602 (more like she's trying to keep them away from each other)
Nude boy and girl sitting on a clothed man's lap: post #1055975
I'm sure there will be other images depicting different situations not covered by these above, and will add them as I come across them later or post them in a later post.