Hi! Try these:
http://www.mangago.me/read-manga/isekai_trip_sex/
http://www.mangago.me/read-manga/koishite_baby_miyako_mimeko/
http://www.mangago.me/read-manga/nirameba_koi/
http://www.mangago.me/read-manga/jelly_pool/
http://www.mangago.me/read-manga/sokuochi_yarichin_yankee/
http://www.mangago.me/read-manga/30_sai_kara_no_coming_out/
http://www.mangago.me/read-manga/ore_to_aitsu_no_jikangai/
http://www.mangago.me/read-manga/momichupa_oppabu_osu_time/
If you want to find more, you can use this tag:
http://www.mangago.me/tag/smaller%20seme/
Hope you enjoy!
Haha I recommend http://www.mangago.me/read-manga/meguro_to_akino_wa_kizukanai/ He’s smaller build-wise, plus it’s just a really good read!!
Can anyone rec any bl w smaller seme