Complex sentence: They decide to sing Laida and Miggy's song' Kailan' with Miggy singing his favorite part, however when Miguel sings Laida gets teary eyed so Miguel stops singing.
Split into simpler sentences: They decide to sing Laida and Miggy's song "Kailan" with Miggy singing his favorite part. However, when Miguel sings, Laida gets teary eyed so Miguel stops singing.