badgenome said:
Ahhh... I had a feeling you weren't telling us the whole story about that fight. Do you want to talk about it, champ? It's okay. We're all

here for you.

If this is indeed a concern, then make sure you and your partner have a conversation.  The first thing is to plan.  If you're gonna have anal, you need to do the prep, which means an enema.

Most US drug stores offer a double-pack of Fleet sodium phosphate enemas, pick up a package.  Read the instructions, whoever is receiving needs to follow them.  You two can do it together, or it can be done in advance by whomever is receiving.  The important thing to understand, is when you feel the need to purge, hold it at least once, though twice would be better.  It's easier said than done.  Do the same with the second bottle.

Someone prepped will not feel the need to have a bowel movement immediately after sex.    The reason someone has a bowel movement after sex is because there is feces in the sigmoid colon.  An enema eliminates that.  If there is any elimination it'll be ejaculate, anal mucus, and lube.  Anal mucus, after two bottles of a sodium phosphate enema should be clear.  It it ends up being any color it'll be yellow-brown from bile.  The anal mucus and lube will mix into a frothy/foamy mix usually white.  If you're not completely clean, the anal mucus will likely be a yellow-brown (from bile) and the frothy/foamy mix will reflect that.

Bottom line, if your partner (or you if you're receiving) is clean there won't be any worries about a bowel movement.   If you use a water enema (not recommended) you may be clean, but it's possible whoever is receiving may expel copious amounts of water and anal mucus during sex.  It may even contain fecal matter, but usually trace amounts.  The only major issue with it is that it introduces water into the rectum, which dilutes the lube.  Typically that means you have to reapply lube.

Tightness, as a problem, is due to a lack of patience.  You can't just insert into the anus and expect it to be like a vagina.  Using fingers to lube the anus and train your partner to relax their anus will go far in making sex pleasurable for both.  Insertion should be taken slow.  Listen to your partner during insertion.  Insert until there is pain, pull back slightly, hold until your partner bears down and relaxes, then push in.  You'll need to do this at lease twice, up to four times depending on your length.  After the anus, the other three are the folds in the rectum.

If you do this, then it won't be so tight that it isn't pleasurable for you or your partner.