Short answer: possibly, under the right conditions. Early research suggests psilocybin and MDMA can increase emotional openness, empathy, and a felt sense of connection for some couples, but findings are preliminary and not consistent.
Several studies and reviews report gains in emotional empathy, intimacy, and shared understanding, with MDMA showing particular promise when trauma strains a relationship. For an overview of social connectedness findings, see this recent review.
Important caveats: experiences can be intense and sometimes increase tension or distrust. Samples are often small, effects rely on self-report, and outcomes depend heavily on setting, support, and follow-up. This is not a shortcut or a replacement for relationship work.
Bottom line: psychedelics may help some couples by lowering defensiveness and opening space for honest engagement, but they are not a fix on their own. Proceed with care and realistic expectations.