Is it normal to sweat between your breasts?
Yep.Totally normal
Yes, sweating between your breasts is normal. Warmth, movement, and skin touching skin can trap heat and moisture there.
That area can get warm and have less airflow, especially in hot weather, during exercise, or under a snug bra. Lots of people sweat there; bodies are not exactly known for staying dry in every crease.
Breathable clothing and gently drying the area can help with comfort. If you also get a persistent rash, soreness, or broken skin, it’s worth getting checked.