Is this ok to wear to a wedding?

Hi, I have a wedding to go to tomorrow, I'm the grooms sister in law and in all honesty I've bought 3 dresses so far, one in a light green that turned out too short, one in nude and one in red- the nude one us beautiful but I feel is too blended with the bride so the best one is red (I'll insert pic) my partner also prefers this dress but I've read so many mixed views online about wearing red to a wedding I just don't know what to do.... my chest is basically flat so I won't have an outrageous cleavage on show like in the pic, infact zero cleavage to he shown and I was going to team with black strappy heels and a little black bag, Thanks in advance for any advice ♥️