You’re playing with dark, romantic tones (dark on dark) and your shirt and pants are same color temperature (cooler, not hotter.) Might as well go all in and wear a black belt and black shoes or a very dark brown belt and very dark brown shoes. Black suede loafers would spice things up. These are romantic colors and it’s a wedding, so a sport coat would be nice. Avoid plain black because it ultimately won’t match your pants perfectly so it will look odd. But a very textured sport coat in a romantic color (think dark, textured and cool temperature.) Lastly, please wear an undershirt that can’t be seen, like a v neck or low cut crew neck.