I guess it is allowed in exceptional cases. For example, you were driving in a car and you need to light up a candle for some urgent reason. Or you were going to the beach in some resort village, suddenly you saw a church, walked in to light up a candle and kiss the icons. Of course, it is desirable to confess it later.
However, when you are going to a festive Liturgy and you have a choice between wearing shorts or pants, and you put on shorts, of course, it is unacceptable. Not only do you (and often it applies to women with open arms, necklines and below the waist) seduce other people, you are also filled with some audacity to appear before God in an inappropriate fashion. In my opinion, shorts or other scant clothing in the church signals the wrong attitude to the spiritual life, the absence of God’s fear in a person.
What makes this way of living the spiritual life wrong? It mixes up the church and the outside world. The Church is just one organization among the many that a person attends. It is definitely a product of secularization, an attempt at leveling the Church today, an attempt to place it among other public institutions (I went to McDonald’s for a snack, then to the subway, then to the market, then to the church to light up a candle, then to the office, and finally went home in the evening). Sounds like it’s nothing special. It’s just a normal human day. However, if a person does not realize that “going to church to light up a candle” is the highlight of his day, then it is a disaster. Instead of touching the sacred, he commits sacrilege. A great many saints said that prayer with a cold heart, inattentive prayer is a sin.
Your clothes, however, are the beginning of your prayer. There is little difference between a layman and a priest. A clergyman does not dare to touch the Holy Table or start a divine service without an undercassock and an epitrachelion. It is absolutely impossible.
So when does a divine service begin for me, a priest? I get up, dress, put on an undercassock, then a cross, read morning prayers, the Rule of Holy Communion. That’s when the divine service begins! Even before coming to the church, I’m already on duty. I’m already preparing to appear before the Most Holy God. Just like any other person. Remember our ancestors. They wore their best clothes to the church. The very best! But not shorts. That’s because I go to serve my beloved God. My clean beautiful clothes are an offering to him, a proof that I want to be pure spiritually too. This is my way of showing my love for God.
Therefore, dear brothers and sisters, let us approach God with fear and faith! The body is the continuation of the soul, and the garment is the continuation of the body. Let us show our love to God in all things and bring Him our utmost sacrifice, even if it is by clothing properly.
Translated by The Catalogue of Good Deeds
Source: https://pravlife.org/ru/content/mozhno-li-v-hram-zahodit-v-shortah
I think it is an error to believe that we can dress seductively outside of Church to begin with. We ourselves are temples of the Holy Spirit as the Scriptures say. Why would God excuse our inmodesty outside the Church building and displeased when we are in the Church? Modesty and shamefacedness as taught by the Holy Apostle Paul stems from a submissive and humble way of heart. Modesty is more than simply covering ones body on occasion. This is what God desires of us., true shame-faced modesty, always. Forgive me.